Legend suggests that St. Patrick used a Celtic shamrock to demonstrate the meaning of the Christian trinity (Father, Son, and Holy Ghost). Although one myth states that St. Patrick inspired this (in a Christian view), earlier legends suggest that the trinity has long been part of the Irish culture. The Celtic shamrocks are renowned for having mystical power and meaning. It's petals will stand upright to warn of an approaching storm. Even today the shamrock is Ireland's most famous symbol. The Celtic shamrock is the unofficial symbol for Ireland